DustDust are fine particles of matter.[1] It generally consists of
particles in the atmosphere that come from various sources such as
soil, dust lifted by weather (an aeolian process), volcanic eruptions,
and pollution.
DustDust in homes, offices, and other human environments
contains small amounts of plant pollen, human and animal hairs,
textile fibers, paper fibers, minerals from outdoor soil, human skin
cells, burnt meteorite particles, and many other materials which may
be found in the local environment.[2]

Three years of use without cleaning has caused this laptop heat sink
to become clogged with dust, and it can no longer be used as it may
overheat.

Domestic dust on a finger

House dust mites are present indoors wherever humans live. Positive
tests for dust mite allergies are extremely common among people with
asthma.
DustDust mites are microscopic arachnids whose primary food is
dead human skin cells, but they do not live on living people. They and
their feces and other allergens they produce are major constituents of
house dust, but because they are so heavy they are not suspended for
long in the air. They are generally found on the floor and other
surfaces until disturbed (by walking, for example). It could take
somewhere between twenty minutes and two hours for dust mites to
settle back down out of the air.
DustDust mites are a nesting species that prefers a dark, warm, and humid
climate. They flourish in mattresses, bedding, upholstered furniture,
and carpets. Their feces include enzymes that are released upon
contact with a moist surface, which can happen when a person inhales,
and these enzymes can kill cells within the human body.[3] House dust
mites did not become a problem until humans began to use textiles,
such as western style blankets and clothing.[4]
Atmospheric

Play media

Presentation on imported dust in North American skies

Large dust storm over Libya

Atmospheric or wind-borne fugitive dust, also known as aeolian dust,
comes from arid and dry regions where high velocity winds are able to
remove mostly silt-sized material, deflating susceptible surfaces.
This includes areas where grazing, ploughing, vehicle use, and other
human activities have further destabilized the land, though not all
source areas have been largely affected by anthropogenic impacts.[5]
One-third of the global land area is covered by dust-producing
surfaces, made up of hyper-arid regions like the
SaharaSahara which covers
0.9 billion hectares, and drylands which occupy 5.2 billion
hectares.[6]
DustDust in the atmosphere is produced by saltation and sandblasting of
sand-sized grains, and it is transported through the troposphere. This
airborne dust is considered an aerosol and once in the atmosphere, it
can produce strong local radiative forcing. Saharan dust in particular
can be transported and deposited as far as the
CaribbeanCaribbean and the
Amazon basin, and may affect air temperatures, cause ocean cooling,
and alter rainfall amounts.[5]
Middle East
DustDust in the
Middle EastMiddle East has been a historic phenomenon. Recently,
because of climate change and the escalating process of
desertification, the problem has worsened dramatically. As a
multi-factor phenomenon, there is not yet a clear consensus on the
sources or potential solutions to the problem.
In Iran, the dust is already affecting more than 5 million people
directly, and has emerged as a serious government issue in recent
years. In the province of Khuzestan it has led to the severe reduction
of air quality. The amount of pollutants in the air has surpassed more
than 50 times the normal level several times in a year. Recently,
initiatives such as Project-
DustDust have been established to directly
study the Middle Eastern dust.
Roads
Main article:
RoadRoad debris
DustDust kicked up by vehicles traveling on roads[7] may make up 33% of
air pollution.[8]
RoadRoad dust consists of deposits of vehicle exhausts
and industrial exhausts, particles from tire and brake wear, dust from
paved roads or potholes, and dust from construction sites.
RoadRoad dust
is a significant source contributing to the generation and release of
particulate matter into the atmosphere.[9] Control of road dust is a
significant challenge in urban areas, and also in other locations with
high levels of vehicular traffic upon unsealed roads, such as mines
and landfill dumps.
RoadRoad dust may be suppressed by mechanical methods like street sweeper
vehicles equipped with vacuum cleaners,[10] vegetable oil sprays,[11]
or with water sprayers. Improvements in automotive engineering have
reduced the amount of PM10s produced by road traffic; the proportion
representing re-suspension of existing particulates has increased as a
result.
Coal
Coal dustCoal dust is responsible for the lung disease known as pneumoconiosis,
including black lung disease that occurs among coal miners. The danger
of coal dust resulted in environmental legislation regulating work
place air quality in some jurisdictions. In addition, if enough coal
dust is dispersed within the air in a given area, in very rare
circumstances, it can create an explosion hazard under certain
circumstances. These circumstances are typically within confined
spaces.

Control
Atmospheric
Most governmental EPAs, including the United States Environmental
Protection Agency (EPA) mandate that facilities that generate fugitive
dust, minimize or mitigate the production of dust in their operation.
The most frequent dust control violations occur at new residential
housing developments in urban areas. United States Federal law
requires that construction sites obtain permits to conduct earth
moving, clearing of areas, to include plans to control dust emissions
when the work is being carried out. Control measures include such
simple practices as spraying construction and demolition sites with
water, and preventing the tracking of dust onto adjacent roads.
Some of the issues include:[citation needed]

US federal laws require dust control on sources such as vacant lots,
unpaved parking lots, and unpaved roads.
DustDust in such places may be
suppressed by mechanical methods,[citation needed] including paving or
laying down gravel, or stabilizing the surface with water, vegetable
oils[11] or other dust suppressants, or by using water misters to
suppress dust that is already airborne.[citation needed]
Domestic

DustDust control is the suppression of solid particles with diameters less
than 500 micrometers.
DustDust poses a health threat to children,[12]
older people, and those with respiratory illnesses.
House dust can become airborne easily. Care is required when removing
dust to avoid causing the dust to become airborne. A feather duster
tends to agitate the dust so it lands elsewhere. Products like Pledge
and
SwifferSwiffer are specifically made for removing dust by trapping it
with sticky chemicals.
Certified
HEPAHEPA (tested to MIL STD 282) can effectively trap 99.97% of
dust at 0.3 micrometers. Not all
HEPAHEPA (type/media) filters can
effectively stop dust; while vacuum cleaners with
HEPAHEPA (type/media)
filters, water, or cyclones may filter more effectively than without,
they may still exhaust millions of particles per cubic foot of air
circulated. Central vacuum cleaners can be effective in removing dust,
especially if they are exhausted directly to the outdoors.
Air filtering appliances differ greatly in their effectiveness. Laser
particle counters are an effective way to measure filter
effectiveness, medical grade instruments can test for particles as
small as 0.3 micrometers. In order to test for dust in the air, there
are several options available. Pre weighted filter and matched weight
filters made from polyvinyl chloride or mixed cellulose ester are
suitable for respirable dust (less than 10 micrometers in
diameter).[13]
DustDust resistant surfaces
A dust resistant surface is a state of prevention against dust
contamination or damage, by a design or treatment of materials and
items in manufacturing or through a repair process[citation needed]. A
reduced tacticity of a synthetic layer or covering can protect
surfaces and release small molecules that could have remained
attached. A panel, container or enclosure with seams may feature types
of strengthened rigidity or sealant to vulnerable edges and joins.
In other contexts

Outer space
Cosmic dustCosmic dust is widely present in space, where gas and dust clouds are
primary precursors for planetary systems. The zodiacal light, as seen
in a dark night sky, is produced by sunlight reflected from particles
of dust in orbit around the Sun. The tails of comets are produced by
emissions of dust and ionized gas from the body of the comet. Dust
also covers solid planetary bodies, and vast dust storms occur on Mars
that cover almost the entire planet.
Interstellar dustInterstellar dust is found
between the stars, and high concentrations produce diffuse nebulae and
reflection nebulae.
DustDust is widely present in the galaxy. Ambient radiation heats dust and
re-emits radiation into the microwave band, which may distort the
cosmic microwave background power spectrum.
DustDust in this regime has a
complicated emission spectrum, and includes both thermal dust emission
and spinning dust emission.[14]
DustDust samples returned from outer space may provide information about
conditions in the early solar system. Several spacecraft have sought
to gather samples of dust and other materials. Among these craft was
Stardust, which flew past
CometComet Wild 2 in 2004, and returned a capsule
of the comet's remains to Earth in January 2006. In 2010 the Japanese
Hayabusa spacecraft returned samples of dust from the surface of an
asteroid.
Atmospheric gallery